Student's error is –5 < x.
Solution:
Step 1: Given inequality
31 < –5x + 6
Step 2: Subtract 6 from both sides of the inequality.
31 – 6 < –5x + 6 – 6
25 < –5x
Step 3: Multiply both sides by –1 to reverse the inequality.
25 × (–1) > –5x × (–1)
–25 > 5x
Step 4: Divide by 5 on both sides.
–5 > x
The correct answer is –5 > x.
Student's error is –5 < x.
